The wife of a jailed human rights activist in China has been prevented from leaving the country to pick up an award on his behalf, friends say.

Yuan Weijing had been due to travel to the Philippines to collect a human rights award for her husband, Chen Guangcheng, who was jailed last year.

But fellow activists say the Chinese authorities revoked her passport and stopped her boarding the flight.

Chen Guangcheng was jailed for damaging property and disrupting traffic.

But his supporters say the real reason Mr Chen, who is blind, was sentenced for four years and three months is because he exposed violations linked to China's one-child policy, including forced sterilisations and abortions.

Prestigious award

Yuan Weijing said the authorities told her on Thursday that they had revoked her passport, even though it was still valid.

She said the authorities then attempted to block her journey both from her home in Shandong province and from the house in Beijing where she stayed in overnight.

Chen Guangcheng has been honoured for his campaigning

She was eventually detained at the airport and her luggage removed from the flight, friends said.

Yuan Weijing had been due to collect the award from the Ramon Magsaysay Award Foundation in Manila - one of Asia's most prestigious honours.

The foundation had named Chen Guangcheng as one of seven winners for his "irrepressible passion for justice in leading ordinary Chinese citizens to assert their legitimate rights under the law".

Mr Chen, 35, has campaigned against what he says are abuses of the Chinese government's one-child policy.

Before being imprisoned, he accused local health workers in Linyi city, in Shandong province, of illegally forcing hundreds of people to have late-term abortions or sterilisations.

China brought in its one-child policy 27 years ago, in a drive to curb population growth, but forced sterilisation and abortion are prohibited.